A 4.89 percent rate hike for Columbus water and sewer customers in 2010 will be the smallest since the city entered into agreements five years ago to fix its system.

That doesn't mean officials are happy.

"Between the U.S. EPA and the Ohio EPA, we're stuck in the vise," City Council President Michael C. Mentel said of the environmental-protection agencies that want Columbus to modernize its sewers, increase their capacity, and stop sending raw sewage into area waterways.

"We have no choice," he said of the increase.

For Columbus customers, the rates approved last night by the City Council will cost an average $40 extra for the year, spread out over quarterly bills for water, sewer and storm-sewer service. The average quarterly bill will increase to $219 from $209.

Residents of 24 suburbs served by the Department of Public Utilities will pay an average of $44 more in 2010. Their quarterly bills will increase to $237 from $226.

"Our rates are still quite affordable," Public Utilities Director Tatyana Arsh said.

Her department surveyed other big cities and found Columbus water and sewer rates to be even with Cleveland, cheaper than Cincinnati and Pittsburgh, and slightly more expensive than such cities as St. Louis and Indianapolis that also have begun massive system improvements.

Columbus must spend about $2.5 billion under agreements with the Ohio EPA to separate sanitary and storm sewers in older parts of the city and increase capacity so waste doesn't overflow into rivers and streams during heavy rains.

Money for the projects comes from ratepayers, not Columbus taxpayers. When work began in 2005, annual water and sewer charges were slightly more than $500 for the average city customer, and officials predicted that they'd hit $913 a year by 2010.

The rates approved last night are below that mark: $876.

Arsh said other cost-saving measures in the department have helped slow rate hikes. Annual increases have topped 7 percent since 2005 and hit 15 percent in 2006 and 2007.

Arsh said the utilities are unlikely to impose double-digit increases again.

Mentel said city officials will press Washington for more aid to Columbus and other cities that face mandates to modernize their sewer systems. Arsh said the city received $10 million in federal economic-stimulus money this year for sewer work.

That's less than 0.5 percent of the $2.5 billion sewer-upgrade plan.

rvitale@dispatch.com